There's sort of two questions here:
1) What design of RTT is the "best" in 2025?
2) What company has the best execution of said design in 2025?
The reason I split the questions out is that there has been a lot of innovation in the RTT space over the last decade. It used to be that everyone was more or less selling their own version of the ARB Simpson, in various sizes. But, hardshell tents have really come up - the iKamper design features a totally new way of fitting a king-sized sleeping area into a smaller package, and that type of design has been mimicked by others in spirit, like Alpha, 23 Zero, and others. Some have their own twist on the design, like 23 Zero's Armadillo X series, which seems to finally do away with the springsteel rods that have been an RTT staple for years.
Recognizing the designs have come a long way, the next question is the craftsmanship and the quality of materials. This can be compared from manufacturer to manufacturer but to some degree you get what you pay for.
If you want an exceptional cheap tent, the Smittybilt Overlander tents are very good value for the occasional weekend out, but will not hold up for long term/heavy use.
We are currently using the Go Overland Canada tent which had the best blend of quality, features, and price we could find; here's our review:
Hi folks, We've recently acquired ourselves a new "Summer Home" in the form of a Go Overland Canada Expedition XL tent. We've only got 6 nights in it so far, but I wanted to share a bit about our really positive experience with this tent. Part 1: (Forum Word Count doesn't like longer threads)...
forum.expeditionportal.com